For a long time now, people have been asking for the plans to the PlyPi. I'm afraid life (and all that entails) has got in the way. But now, behold! I've got the plans scanned into a PDF file. They even seem to print at the right size on my end (which, in my opinion, is as close to a miracle as anything I've ever seen). So hopefully they will be useful to you.
One thing I managed to leave off the accompanying text - it's of course possible to make the PlyPi without an HDMI socket hole. You might need to adjust the plans a little - but really, the skies are the limit! Well, they are when you attach a RPi to a weather balloon, anyway...
If you're pleased with the plans, please consider sending a small donation. It might not seem much, but it might make a huge difference to me.
Anyway, have fun!
The PlyPi Plan